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A009515 E.g.f. sin(x*tan(x)) (even powers only). 2
0, 2, 8, -24, -4544, -333920, -26272896, -2354853760, -233143441408, -22905309777408, -1339233237800960, 428177363623094272, 310125853369485017088, 153488683972244927062016, 72759436391841580585680896 (list; graph; refs; listen; history; text; internal format)
OFFSET

0,2

LINKS

Table of n, a(n) for n=0..14.

FORMULA

a(n)=(sum(m=0..n-1/2, binomial(2*n,2*m+1)*(sum(j=2*m+1..2*n-2*m-1, binomial(j-1,2*m)*j!*(-1)^(n+m+j)*2^(2*n-2*m-j-1)*stirling2(2*n-2*m-1,j))))). - Vladimir Kruchinin, Jun 23 2011

MATHEMATICA

terms = 15;

egf = Sin[x*Tan[x]] + O[x]^(2 terms + 1) ;

Partition[CoefficientList[egf, x] * Range[0, 2 terms]!, 2][[All, 1]] (* Jean-François Alcover, Sep 24 2019 *)

PROG

(Maxima)

a(n):=(sum(binomial(2*n, 2*m+1)*(sum(binomial(j-1, 2*m)*j!*(-1)^(n+m+j)*2^(2*n-2*m-j-1)*stirling2(2*n-2*m-1, j), j, 2*m+1, 2*n-2*m-1)), m, 0, n-1/2)); /* Vladimir Kruchinin, Jun 23 2011 */

CROSSREFS

Sequence in context: A331001 A050971 A118855 * A309088 A070944 A278836

Adjacent sequences:  A009512 A009513 A009514 * A009516 A009517 A009518

KEYWORD

sign

AUTHOR

R. H. Hardin

EXTENSIONS

Extended with signs by Olivier Gérard, Mar 15 1997

STATUS

approved

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Last modified August 16 05:55 EDT 2022. Contains 356160 sequences. (Running on oeis4.)